Mothproofing wool

ABSTRACT

A VERY LIMITED GROUP OF QUATERNARY AMMONIUM COMPOUNDS WERE FOUND TO EFFECTIVELY MOTHPROFF WOOL. TRICAPRYLYLMETHYLAMMONIUM CHLORIDE (ALIQUAT 336), DIDECYLDIMETHLAMMONIUM CHLORIDE (ALIQUAT 203), AND DIOCTYLDIMETHYLAMMONIUM CHLORIDE (ALIQUAT 202) AT ADDON LEVELS AS LOW AS 0.5% PROVIDED VERY GOOD PROTECTION AGAINST BOTH BLACK CARPET BETTLE AND WEBBING CLOTHES MOTH LARVAL FEEDING.

United S tates Patent 015cc 3,746,767 Patented July 17, 1973 3,746,767 MOTHPROOFING WOOL Anthony M. Schwartz, Rockville, and Charles A. Rader, Laurel, Md., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Jan. 7, 1971, Ser. No. 104,762 Int. Cl. A01n 9/20 U.S. Cl. 424-329 7 Claims ABSTRACT OF THE DISCLOSURE A very limited group of quaternary ammonium compounds were found to effectively mothproof wool. Tricaprylylmethylammonium chloride (Aliquat 336), didecyldimethylammonium chloride (Aliquat 203), and dioctyldimethylammonium chloride (Aliquat 202) at addon levels as low as 0.5% provided very good protection against both black carpet beetle and webbing clothes moth larval feeding.

A non-exclusive, irrevocable, royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sublicenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to the treatment of wool and other animal hair and keratinous material to render it resistant to attack by moths. More particularly, it relates to the treatment of wool with a certain very limited class of quaternary ammonium compounds to impart durable moth-resistant properties without introducing toxicity or other hazardous or disadvantageous effects to the wool.

The art of mothproofing Wool is old and extensive. The most widely used chemical method is to impregnate wool with a compound that discourages the moth larvae from eating, either by being distasteful and therefore repellent or by being toxic. A great variety of compound representing many chemical types have been described as mothproofers in both the patent and the journal literature. Among these compounds are several of the long chain quaternary ammonium type. However, none, to our knowledge, has the specific structural features and correspondingly advantageous performance characteristics of the compounds used in the present invention.

In order to determine the efllcacy of a method of treating wool to render it mothproof or to determine the efficacy of a compound or other substance as a mothproofing agent, the results obtained with the method or performance of the compound as a mothproofing agent must be considered.

The following are the performance requirements that should be considered in the determination of the mothproofing eflicacy of a method or a compound.

(1) It must effectively protect the wool from larval attack when present in relatively small amounts, generally less than 2.0% relative to the weight of wool. The effectiveness is tested by exposing the wool, under wellcontrolled conditions, to the larvae for a specified time. Damage is estimated by weight loss, by weight of larval excrement, and by visual inspection.

(2) It must not alter the handle, color or other functional properties of the wool.

(3) It must not be toxic, and must not cause dermatitis, itching, etc., to the user of the woolen garment or goods.

(4) 'It must remain on the goods and be effective when subjected to multiple washings and drycleanings.

(5) It must be easy to apply to the goods, either during or after fabrication, by processes that do not matt or shrink or otherwise alter the desirable characteristics of the wool.

The more successful of the quaternary ammonium types previously used for mothproofing have adequately met requirements 2 and 3 above, and to a certain extent requirement 5. Requirements 1 and 4, elfectiveness and durability, have not, however, been adequately satisfied. The best compounds to date, and their performance characteristics, are described by Freeland and Williams, Textile Research Journal 37, 408-416 1967). All of them are characterized by having a single long chain alkyl group on the quaternary nitrogen atom. The chain length of this group is in the usual surfactant range, that is 12-18 car bon atoms. The remaining groups on the nitrogen are the usual nonsurface active lower alkyl pyridyl or benzyl, and together they take up the three valencies on the nitrogen other than that taken up by the long chain alkyl group.

It is an object of this invention to provide mothproofing agents that exhibit all of the above listed desirable performance requirements.

Another object of this invention is to provide a method of treating wool which will render the wool mothproof.

In general, according to this invention, wool is made mothproof by treating it with a quaternary ammonium compound of one of the following general formulas wherein R, R' and R" are straight chain alkyl groups of 8 to 10 carbon atoms, a and b are alkyl groups of 1 to 3 carbon atoms, X" is an anion such as Cl, Br-, SO CH and SO C H that together with the nitrogenous cation forms a soluble salt. This treatment combines all the desirable properties of a mothproofing agent including exceptional durability to washing and drycleaning and effectiveness in low concentrations of the selected compound.

The compounds of this invention are soluble in water and may be applied to woolen goods by padding, soaking, or spraying. The effects of temperature, pH, and inorganic salts in the bath and the extent and rate of take-up are those expected when a typical cationic surfactant is applied to Wool. The compounds of this invention, however, combine unexpectedly high toxicity to moth larvae with high resistance to removal by laundering or drycleaning. In addition, solutions of the compounds in non-aqueous solvents may also be used to treat the wool.

The following examples demonstrate the application of the process:

EXAMPLE 1 Application to woven woolen piece goods by padding Eight by twelve inch swatches of clean wool flannel were treated in a conventional padding machine with a 0.3% solution of tricaprylylmethylammonium chloride (Aliquat 336) in which the three caprylyl groups are a mixture of C and C The treating bath also contained .01% of Tergitol NPX the monoether of nonyl phenol with a polyethylene glycol mixture having an average chain length of 10.5 ethylene oxide (a nonionic surfactant) that served as a wetting agent. The pad roll pressure was 20 p.s.i., providing a wet pick-up of 108%. After drying, the add-on of quaternay compound was measured at 0.32% on the weight of wool. The material thus treated was resistant to the attack of black carpet beetle larvae and webbing clothes moth larvae when tested by the C.S.M.A. (Chemical Specialties Manufacturers Association) and A.A.T.C.C. (American Association of Textile Chemists and Colorists) test methods.

3 EXAMPLE 2 Application by soaking Raw wool was scoured in a conventional scouring procedure, except that the last rinse bowl, instead of containing water contained a .0l% solution of didecyldimethylammonium chloride (Aliquat 203). The wool was left in this bath for 4 minutes. The add-on was determined after squeezing and drying in the conventional manner, and was 0.7%. This material was resistant to moth larvae and retained its resistance through all subsequent manufacturing steps to the final woven fabric. Tables I-II show the results obtained by immersing accurately weighed wool swatches in aqueous quaternary salt solutions. Table I shows the percent depletion of the bath and the percent add-on of quaternary salt on the wool. Tables II and III show the resistance of quaternary treated wool to black carpet beetle larvae and to webbing clothes moth larvae respectively. Add-on levels as low as 0.5% provided very good protection against both black carpet beetle and webbing clothes moth larvae feeding.

Minimum effective levels ofthe quaternary salts as insect deterents were determined using tricaprylylmethylammonium chloride (Aliquat 336) as the mothprooiing agent. Accurately weighed Wool swatches were immersed and agitated in aqueous solutions of the quaternary in a borax bufi'er of pH 9.2. The wool-liquor ratio was 1:20. The treatment was done at 38-40" C. for two hours. Concentration of the quaternary bath was determined before and after the adsorption treatment, percent depletion of the bath and percent add-on of quaternary on the wool calculated, and effectiveness of the treatment against black carpet beetle larvae and webbing clothes moth larvae determined. The data are shown in Tables IV to VI.

The data of Table V show that the treated wool containing the 0.25% and 0.50% quaternary add-on were satisfactorily protected against black carpet beetle larvae feeding. The treated wool containing 0.10% quaternary add-on just failed with 0.52 mg. excrement (0.50 mg. or less in passing). However, as shown in Table VI, treated wool containing 0.10%; and higher quaternary add-on levels were protected from Webbing clothes moth larvae.

As shown in Tables VII and VIII, even at add-on levels as low as 0.15%, the quaternary salt retained its effectiveness during storage against both black carpet beetle and webbing clothes moth larvae feeding. As shown by the excrement weights per larva and the adjusted weight losses, wool swatches treated with tricaprylylmethylammonium chloride and aged for periods up to nine months were satisfactorily protected at 0.15 to 0.50% add-on levels.

TABLE H.RESISTANCE OF QUATERNARY AMMONIUM TREATED WOOL TO BLACK CARPET BEETLE Quaternary Excrement adden, per larva, Mortality,

Compound percent mg. percent Dioetyldimethylarmnonium 0. 4 0. 42 0 chloride (Aliquat 202). 1. 0 0. 25 0 2.0 0. 30 0 Untreated check 2. 19 0 Trieaprylylmethylammonium 0. 5 0. 28 0 chloride (Alquat 336). 1. 0 0. 25 0 2.0 0. 25 0 Untreated cheek- 1. 91 0 Didecyldimethylammonium 0. 5 0. 28 0 chloride (Aliquat 203). 1. 0 0. 26 0 2. 0 0. 27 0 Untreated check 2. 19 0 NOTB.The fabric is considered satisfactorily resistant to black carpet beetle larvae if the average quantity of excrement per larva is not over 0.5 mg. provided that no single value is over 0.6 mg., and the untreated check is over 1.5 mg.

TABLE IIL-RESISTANCE OF QUATERNARY AMMONIUM HALIDE TREATED WOOL TO WEBBING CLOTHES MOTH LA RVAE Quaternary Adjusted add-on, weight loss, Mortality, Compound percent mg. percent Dioctyldimethylammonlum 0. 4 7. 71 52. 5 chloride (Aliquat 202) l. 0 4. 28 B5 2. 0 3. 58 77. 5 2. 8 3. 41 B5 3. 4 2. 77 97. 5

Untreated check 31. 46 12. 5

Tricaprylymethylarnmonium 0. 5 5. 47 77. 5 chloride (Aliquot 336) 1. 0 3. 82 87. 5 2. 0 1. 63 100 3. 0 l. 34 02. 5 4. 0 2. 18

Untreated check 36. 63 17. 5

Di decyldimethylammonium 0. 5 5. 82 55 chloride (Aliquot 203) l. 0 3.69 82. 5 2. 0 0. 93 97. 5 2. 9 1. 45 E7. 5

Untreated check 31. 46 12. 5

Nora-Fabric is considered satisfactorily resistant to webbing clothes moth larvae it the average weight loss due to feeding is not more than 8 8 mg.; provided the weight loss of no individual sample is more than 10 mg. The weight loss of the untreated check should be 30 mg. or more.

TABLE L-ADSORPTION OLE QUATERNARY AMMONIUM HALIDES ONTO WOOL Initial concentration of the quater- Temperature Time of Quaternary nary bath, of adsorption adsorption Exhaust add-on, percent active treatment, treatment, oi bath, on wool, Compound ingredien 0. hours percent percent Dioctyldimethylarnmonium chloride (Aliquat 202) 0. 020 38-40 2 100. 0 0. 4 0.050 38-40 2 98. 0 1. 0 0. 38-40 2 98 2.0 0. 38-40 2 87 2. 6 0.200 38-40 2 84 3. 4

Tricaprylylmethylammonium chloride (Aliquate 336)-- .z 0. 200 3537 2 98. 8 4. 0 0. 150 35-37 2 100 3. 0 0.100 35-37 2 100 2. 0 0. 050 35-37 2 100 1. 0 0. 025 35-37 2 100 0. 5

Didecyldimethylammonium chloride (Aliquat 203)- 0. 025 38-40 2 100 0. 5 0. 050 38-40 2 100 l. 0 0. 100 38-40 2 100 2.0 0. 150 38-40 2 98 2. 9 0. 200 38-40 2 99 3. 9

TABLE IV Initial concentrntion oi Exhaust Quaternary quaternary of bath, addon, Compound bath (percent) percent percent Tricaprylyhnethylammonium chloride (Aliquat 336) 0.0025 100 0.05 0. 0050 100 0. 10 0.0125 100 0.25 0. 0250 100 0.50

TABLE V Excrement Mor- Azld-on, per larva, talit Compound percent mg. percent Tricaprylylmethylammonium chloride (Aliquat 336) 0.05 0.72 0. 0. 52 0 0.25 0.31 0 0. 50 0.30 0

None: Untreated check 1. 75 O TAB LE VI Adjusted Mor- Add-on, weight loss, tality, Compound percent mg. percent Tricaprylylmethylamrnoniurn chloride (Aliquot 336) 0.05 10. 00 73 0.10 5. 58 70 0. 25 2.86 80 0.50 1. 89 02 None: Untreated check 36. 26 12 wherein R, R and R" are selected from the group consisting of straight chain alkyls containing from 8 to 10 carbons, a and b are methyl, X is an anion selected from the group consisting of Cl, B1 SO CH and SO C H said treatment adding to the wool an effective amount of at least 0.15% of an aforesaid quaternary ammonium compound.

2. The process of claim 1 wherein R, R and R are alkyls containing 8 carbons and X- is Cl-.

3. The process of claim 1 wherein R and R are alkyls containing 8 carbons and X- is Cl.

4. The process of claim 1 wherein R and R are alkyls containing 10 carbons and X is Cl-.

5. The process of claim 1 wherein the quaternary ammonium compound is applied by padding the wool with an aqueous solution of said compound.

6. The process of claim 1 wherein the quaternary ammonium compound is applied by immersing the wool in a solution of said compound.

7. A process for treating wool to make the wool resistant to the larval feeding of the black carpet beetle and the Webbing clothes moth consisting of immersing and agitating the wool in an aqueous solution Containing an effective amount of at least 0.005% of a quaternary ammonium compound selected from the group consisting of tri(octy1-decyl)methylammonium chloride, dioctyldimethylammonium chloride, and didecyldimethylammonium chloride, said aqueous solution containing a borax buffer of pH 9.2 and said treatment being done at 38 to C. for 2 hours.

TABLE VIL-EFFECTIVENESS OF MOTHPBOOFING AGENT AGAINST BLACK CARPET BETTLE LARVAE DURING STORAGE Excrement per larva, mg.

Add-on, Initial l-month 2-months 3-months Q-months Compound percent test aging aging aging aging Trioaprylylmethylammonium chloride (Aliquat 336) 0.15 0.39 0.29 0.39 0. 35 0.30 0.25 0.31 0. 30 0.32 0. 34 0. 26

None, Untreated h k 2.10 1. 90 1.62 1. 73 2.00

TABLE VIIL-EFFECTIVENESS OF MOTHPROOFING AGENT AGAINST WEBBING L U G S ORAGE C OTHES MOTH LARV AE Adjusted weight loss of wool, rug.

Add-on,

Aged Aged Aged Aged Quaternary compound percent Imtial l-month 2-months 3-months Q-months Tricaprylylmethylammonium chloride (Aliquat 336) 0.15 4. 92 5. 00 7. 27 6. 31 5. 97 0. 25 2. 29 3. 89 5. 61 3. 77 4. 49

None: Untreated wool-.- 41. 32 54. 84 43. 33.19 35.00

Moth larvae mortalities were also determined. Mortality was 70-100% for the various Aliquat-treated samples and 747% for the untreated wool.

We claim: 1. A process of mothproofing wool consistlng of treating the Wool with a quaternary ammonium compound having 55 a formula selected from the group consisting of and References Cited UNITED STATES PATENTS 3,033,704 5/1962 Sherrill et a1. 117-1385 3,058,881 v10/1962 Wilde 117-1385 X 3,247,058 4/1966 Hyman 117-138.5 X

OTHER REFERENCES Freeland et a1.: Textile Research Journal, vol. 37, pp. 408-16, May 1967.

MeCutcheons Detergents and Emulsifiers 1969 Annual, p. 42.

Tolgyesi et al.: Chem. Tech., pp. 27-30, January 1971.

STANLEY J. FRIEDMAN, Primary Examiner US. Cl. X.R. 117-1385 

